Update Neon colors and show color circles in theme picker

- Update NeonMoodTint to use synthwave colors matching Neon voting style
  (cyan, lime, yellow, orange, magenta)
- Replace text label with 5 color circles in theme preview Colors row
- Remove unused textColor customization code and picker views
- Add .id(moodTint) to Month/Year views for color refresh
- Clean up various unused color-related code

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Shared/Persisence/DataController.swift

@@ -67,4 +67,21 @@ final class DataController: ObservableObject {
             Self.logger.error("Failed to save context: \(error.localizedDescription)")
         }
     }
+
+    /// Refresh data from disk to pick up changes made by extensions (widget/watch).
+    /// Call this when app becomes active.
+    func refreshFromDisk() {
+        // SwiftData doesn't have a direct "refresh from disk" API.
+        // We achieve this by:
+        // 1. Rolling back any unsaved changes (ensures clean state)
+        // 2. Triggering listeners to re-fetch data (which will read from disk)
+        modelContext.rollback()
+
+        // Notify listeners to re-fetch their data
+        for closure in editedDataClosure {
+            closure()
+        }
+
+        Self.logger.debug("Refreshed data from disk")
+    }
 }